* Riki is known for being a successful support killer, something Shadow Shaman is very vulnerable to.
* Smoke Screen is particularly devastating to Shadow Shaman. With neither his various disables nor a solid health pool Shadow Shaman is usually dead. This forces Shadow Shaman to buy a Force Staff if he finds himurself in this scenario and buy Sentry Wards if you have the money.

* With Smoke Screen, Riki will silence and catch Medusa in a surprise with high miss chance flushing her from positions easily in team fights.
* He can deal a huge amount of damage through Cloak and Dagger, even through Mana Shield.

* Sniper can easily destroy Mass Serpent Ward from long range

* Sniper can outrange both Medusa's arrows and Stone Gaze, allowing him to focus her down during a teamfight.
Additional:
* Medusa is a fairly immobile hero that deals damage around her with Split Shot. Sniper should outrange her and should stay out of harm's way from Split Shot.
* More importantly, Sniper should have enough attack range to fire at Medusa during her Stone Gaze without turning to stone, so the ultimate is mostly wasted against him.

* Support heroes with low mobility can be slowed further by Incapacitating Bite, and swarmed by Spiderlings for an easy kill: Shadow Shaman, Visage, Dazzle, Rubick, Lich.

* Webbed areas can be used to hit and run, covering distance hastily weakening her on the way and initiating ganks.
* Even though Medusa can hunt down Spiderlings easily when given enough range, Silken Bola will cause her attacks to miss and get her swarmed in no time.
* Medusa usually does not build a Black King Bar to benefit from Mana Shield fully while Broodmother can fit a Diffusal Blade to burn away all of Medusa's mana.
Additional:
* Spin Web will allow Broodmother to pick her own fights and sometimes slip away to ambush Medusa.
* Though Medusa's Split Shot and Mystic Snake can help Medusa deal with Broodmother's spiderlings, Broodmother will create too much of them for her to handle, allowing her to outnumber Medusa's targets from Split Shot and shield her team in process.

* Arc Warden with his Magnetic Field will protect allies from Mass Serpent Ward.

* He can use either his own or his double's Flux to bypass the spellblock from Linken's Sphere, using the leftover Flux + Spark Wraith to slow Medusa's already low move speed to a crawl.
* Arc Warden has a farming advantage with double Hand of Midas, and can generally bully Medusa with other items that benefit from duplication.

* With 4 active abilities, Shadow Shaman is weak against silencing foes such as Silencer, Drow Ranger and Death Prophet.

* Silencer burns easily through her effective HP from Mana Shield, by taking away her intelligence.
* Arcane Curse punishes her repeatedly casting Mystic Snake to keep her mana pool high. He can force her to use Manta Style before he has cast Global Silence and Medusa usually does not want to build Black King Bar.

* Nyx Assassin, Bounty Hunter and Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.

* Medusa is especially vulnerable to Essence Shift, as both strength and intelligence contribute to her effective HP, while agility contributes to her damage.
* Dark Pact when timed right can be used to dispel Stone Gaze right after it petrifies Slark, allowing him to keep attacking Medusa throughout the duration.
Additional:
* Medusa cannot chase Slark in any way and has no disable beyond her ultimate, making her unable to stop him getting away and regenerating before coming back to finish her off.
* Essence Shift particularly removes 1 intelligence point per hit, thus lowering Medusa's mana pool's cap and leaving her much more vulnerable in prolonged fights.

* Nyx Assassin, Bounty Hunter and Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.

* Level 4 Mana Burn burns of Medusa's mana every 5 seconds if Medusa only increases her mana pool with intelligence. Additionally, 70% of the Mana Burn damage gets mitigated by Mana Shield, burning even more mana.
* Due to the passive nature of Mystic Snake and Split Shot, it can possibly proc Nyx's Spiked Carapace if he's within range of Medusa's abilities and isn't invisible.
* Medusa lacks single target damage, making Nyx with Aghanim's Scepter extremely hard to deal with if Medusa is the team's main damage source.
Additional:
* With her passive Split Shot, Medusa can be easily interrupted by Spiked Carapace during combat, especially during her precious Stone Gaze.
* Mana Burn quickly destroys Mana Shield, especially if Medusa only increases her mana pool by bolstering intelligence (which has the added bonus of increasing Mana Burn's damage).
* Uncontrollable damage from Mystic Snake and Split Shot can trigger Spiked Carapace.
* Medusa lacks single target damage, making a Burrowed Nyx Assassin hard to kill.

* With 4 active abilities, Shadow Shaman is weak against silencing foes such as Silencer, Drow Ranger and Death Prophet.

* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark,Drow Ranger.

* Mirana can disturb Shadow Shaman's channeling even if he is under the effect of invisibility thanks to Sacred Arrow.
* Mirana armed with an Aghanim's Scepter is known to be able to quickly burst down heroes - especially supports. Together with Ethereal Blade the bullying towards Shadow Shaman can continue for the whole match.

* As a caster, Anti-Mage's Mana Break and Mana Void are highly effective against him.

* Anti-Mage easily destroys Mana Shield with Mana Break, especially once he has Manta Style.
* Anti-Mage effectively avoids Stone Gaze with Blink, and can reinitiate after its duration is over.
Additional:
* Mana Break burns Medusa's mana easily, especially when coupled with a Manta Style.
* Can easily initiate on Medusa with Blink, burning her mana or forcing her to use Stone Gaze.
* Mana Void is effective against Medusa's big mana pool and mana usage, presenting a huge hazard to Medusa's allies around her since her Mana Shield still gives her some protection if she has mana.

* Ursa's status resistance from Enrage reduces duration of Medusa's Stone Gaze.
* Ursa can stack damage with Fury Swipes easily against her Mana Shield in a prolonged team match.
Additional:
* Medusa's tankiness doesn't help her very much against Fury Swipes in long teamfights.
* With no escape mechanism and a slow movement speed, getting jumped on by Ursa usually spells a quick end for Medusa in the early game.

* With Static Link, Razor can effectively make Medusa useless in teamfights by reducing her main damage output. It can, however, be blocked by a Linken's Sphere.
* Plasma Field allows Razor to get on top of Medusa, slowing her already slow movement speed to a mere crawl.
* Eye of the Storm capitilizes on Medusa's low armor and causes her to be very vulnerable, even through Mana Shield.

* Phantom Lancer with Diffusal Blade will very quickly burn Medusa's mana, making Mana Shield significantly less effective.
* Doppelganger's 1 second invulnerability can be used to dodge Medusa's petrification from Stone Gaze, as well as Mystic Snake.
* Phantom Lancer's illusions outnumber Medusa's targets from Split Shot, likely shielding his team in the process.

* Reincarnation allows Wraith King to survive Shadow Shaman's initial chain of disables and Serpent Ward attacks.
* Short cooldown of Wraithfire Blast is ideal for interrupting Shackles.

* Fiend's Grip provides mana drain, which can heavily damage Mana Shield and prevent Medusa from using Stone Gaze.
* Even if she does use Stone Gaze, Nightmare can buy enough time to protect allies and reset the fight.
Additional:
* Fiend's Grip leaves Medusa defenseless, since not only does it deal damage, it also drains mana.

* Ether Shock is a great farming ability as a handy short-cooldown nuke.
* Hex and Shackles gives Rubick extra lockdown potential in ganks and teamfights.
* Mass Serpent Ward, should Rubick steal, serves as a powerful source for teamfighting, pushing, and acquring Roshan.
* Arcane Supremacy allows Rubick to cast Hex and Shackles at a further distance, which keeps Rubick at a safer position compared to Shadow Shaman.
* Rubick can interrupt Shackles by casting Telekinesis.

* Medusa lacks mobility or escape mechanisms. Earth Spike and Hex can neutralize her strong damage potential and allow for Lion's team to focus her down.
* In addition to easily breaking her commonly bought Linken's Sphere with its low cooldown, Mana Drain can quickly drain her Mana Shield, making her far less tanky.

* Dragon Knight can simply tank and destroy all Shadow Shaman's Serpent Wards.

* Waveform allows Morphling to escape from Mass Serpent Ward
* Morphling can interrupt Shadow Shaman while he is shackling an ally with Adaptive Strike (Strength).
* With Ethereal Blade Morphling can quickly burst him down before he even has a chance to react.

* Omniknight can dispel Hex or Shackles with Heavenly Grace. He can also heal teammates which you disabled. The same goes to Abaddon's Aphotic Shield .

* Lone Druid's early game is good against slow, squishy supports since his bear is very strong early game and an Entangling Claws proc almost always guarantees a kill: Ancient Apparition, Crystal Maiden, Shadow Shaman, etc.

* With 4 active abilities, Shadow Shaman is weak against silencing foes such as Silencer, Drow Ranger and Death Prophet.

* Nyx Assassin, Bounty Hunter and Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.

* Heroes with channeling spells are very easy targets for Jakiro's abilities: Crystal Maiden, Dawnbreaker, Enigma, Pudge, Shadow Fiend, Shadow Shaman, Warlock.

* By simply using Aphotic Shield, Abaddon can easily save his allies from heroes that apply long disables, such as Lion or Shadow Shaman.

* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark,Drow Ranger.

* Heroes that have a channeled ability that can be interrupted by Meat Hook: Shadow Shaman, Witch Doctor, Enigma, Bane.

* Heroes with extremely slow movement speed will cripple against Solar Bind: Medusa, Viper

Additional:
* Will-O-Wisp will keep Medusa busy after she got hit by Blinding Light.

* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.

* Heroes who take a long time to become strong are in for a rough mid game, such as Outworld Destroyer, Magnus, Medusa, and Anti-Mage.

* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, Beastmaster, Bloodseeker, Clockwerk, Doom, Shadow Shaman.

* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.

* EMP allows Invoker to burn Medusa's mana to weaken Mana Shield.
* Medusa's lack of mobility makes her easy to kite with Invoker's spells.
Additional:
* EMP is a large mana burn nuke which can hit Medusa's Mana shield with enough damage to lose even more mana.
* Deafening Blast disarms Medusa's ability to deal pseudo-AOE damage during teamfights.
* Cold Snap allows the opposing team to repeatedly stun Medusa in short succession, preventing her from successfully casting her ultimate due to its long cast time.

* Bulwark can make each of Medusa's attacks target him instead, reducing Medusa's contribution on team fights.
* Spear of Mars stuns Medusa and also pushes her away from teamfights, taking advantage of Medusa's low mobility.
* Arena Of Blood blocks Medusa's attacks from outside the arena.

* Spectre's entire ability set is designed to get to and destroy heroes that stay in the backlines, both carries (like the aforementioned Drow Ranger and Sniper) and supports (like Dazzle and Shadow Shaman).

* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark,Drow Ranger.